Disposable absorbent articles, in particular, disposable diapers including pull-on diapers, often include elastic features designed to provide a more comfortable and contouring fit to a wearer (a baby or an adult suffering from incontinence) by conformably fitting the article to the wearer and sustaining this fit throughout the time of wear. Examples of such features include elastic side panels, elastic waist features, elastic leg cuffs and the like, providing expansion and contraction in certain directions to ensure a sustained fit. Often, such elastic features are required to be breathable to provide a desired comfort to the wearer.
The elastic features of disposable absorbent articles are often made of compound materials comprising elastic films (including breathable films) or elastic scrims, laminated with non-woven fabrics providing desired surface properties and aesthetics of the compound material. The elastic properties of such compound materials are often provided by activating the elastic properties which can be latent before the activation, that is the compound material which is non-elastic by itself before the activation becomes elastic after the activation as it were itself elastic.
One of the activation techniques can include mechanical stretching, preferably incremental mechanical stretching of the compound material to provide permanent elongation of the non-woven substrate(s) comprising the compound material to enable the elastic member(s) of the compound material, such as the elastic film or elastic scrim, to stretch under a tension force applied to the compound material. When the elastic member is allowed to contract, the permanently elongated nonwoven fabric wrinkles or shirrs to contract in dimension along with the elastic member. Such a compound material becomes elastic or elasticized material.
The elasticized materials are often expensive because they can not only include expensive elastic materials but also require difficult process operations of handling elastic films and scrims, for example, sophisticated cut and slip operations. Because the elasticized features are relatively expensive, they normally contribute to a higher cost of the disposable absorbent articles including such features.
Further, the elastic features of disposable absorbent articles are often required to have different elastic properties in different directions corresponding with the directions of different tension forces to which an absorbent disposable article can be subjected during wear. For example, elastic side panels can require different tension forces directed to the waist area rather than to the leg area of the article. This can be difficult to provide by use of elastic films or elastic scrims, which normally extend throughout the entire area of the side panels and, therefore, can be not sufficient to provide the desired different directional stretch properties. Alternatively, use of multiple, discrete pieces of elastic films or scrims positioned along the desired directions of the tension forces can be expensive due to the difficulties in handling the discrete pieces of elastic films or elastic scrims.
Therefore, it would be beneficial to provide a relatively low cost disposable absorbent article having desired elastic features. Further, it would be beneficial to provide a relatively low cost disposable absorbent article including desired elastic features having desired stretch properties in desired directions. It would be also beneficial to provide a relatively low cost elastic material suitable for use in designing such elastic features. Further, it would be beneficial to provide a latent elastic material suitable for use in disposable absorbent articles, which can be activated when desired, for example, during the production of the article to provide a desired elastic feature. Furthermore, it would be beneficial to provide a relatively low cost method of manufacturing such elastic and latent elastic materials.